Paul C. Buff, Inc. Technical Forum

I'm getting some strange behavior with my remote camera set-up and looking for some insight. Basically, I'm getting erratic firing - pushing the test button on the CST only fires the camera about 20% of the time. I'm using a Flash Zebra 3 pin (item #0090) shutter release cable for Canon to use with my 5D and 20D, and a set of CyberSyncs. Here's the run down:

Using 1 CST to trigger 1 CSRB connected by Flash Zebra 3 pin cable to Canon 20D the shutter doesn't consistently trip. Sometimes it takes 2 or 3 tries, pushing the test button, before it works. Once it does fire, you can continue rapid-firing indefinitely without problem. But, as soon as you pause for more than a few seconds, the problem returns. It only fires maybe 20 % of the time. I've set the lens to manual focus, set the camera to AI Servo, pushed the white button down on the cable, and turned off the "auto-off" sleep function in the camera. I can't think what other settings exist that might be causing the problem. With the transmitter on the hot shoe of another camera (i.e., triggering by firing the second camera instead of using the CST test button) the same thing occurs.

Here's where it gets even weirder: When I use the 5D in place of the 20D, with all other variables the same, the exact same thing occurs EXCEPT when the switch on the Flash Zebra cord is turned OFF (white button up). On the 20D this disables the trigger. But on the 5D it makes the transmitter trigger 100% of the time! And this is not a bad cable or bad transmitter. A co-worker of mine has the EXACT same set-up - same cameras, same CyberSyncs, same Flash Zebra cable - and he gets the same results.

Here's the kicker: it seems to be a compatibility issue, because when I use Pocket Wizards (not mine) instead of CyberSyncs everything works as it should BUT only if the Flash Zebra cable is connected to the PW receiver's "flash" jack. Using the "Camera/flash" jack, NOTHING works.

What is going on here? If it was just me, I'd think I was completely crazy. But like I said, a co-worker has all the same equipment, and he gets all the same results. Any ideas?

Thanks,

Jason

First, if you have not done so, see if you can use his cable with your camera and recievers. If possible, try swapping each component one at a time until you see a difference. Also, try turning off auto review. Also, some cameras have a release priority/focus priority setting. If your camera has this, set it to release priority. This allows the shutter to trip even if not in perfect focus.

One more possibility. If you familiar and equiped to do so, a continuity test/comparison on the two cables may indicate a difference. If the cord is wired incorectly, I can easily see this characterization.

Thanks for the quick reply. Switching out components doesn't solve this problem. Like I said (though perhaps I was unclear), a co-worker has all the same equipment (that is same models) and has all the same problems with his set up. That is, we have two different sets of everything, and no matter what combination we use, we have the same problems. We think it's specifically a CyberSync issue with the Canon 20D - swap out the camera to a different model (5D) and the set-up works. Swap out the remotes to a different model (Pocket Wizards) and the set- up works. Use CyberSyncs and 20D together and we get misfires.

As for your other suggestions - on the 20D the AI-Servo focus function (I believe) is release-priority. At any rate, I've tried all the other focus settings, but that doesn't seem to change anything. Auto review is off, so that's not it either....

Any other ideas? Any one?

Thanks.

Ok, I've done some more testing and located the problem. I'll post it here, in case anyone else runs into the same trouble. On the Canon 20D (as with most cameras) pushing the shutter release button half way activates the meter display in the viewfinder. I've found that using the CST to release the shutter, it requires one push of the test button to do the same thing. That is, when looking through the viewfinder, push the test button once, and you'll see the meter display activate. Push the test button again, and the camera will fire. From that point on, the camera will continue to fire with each push of the test button. BUT, if you wait more than a few seconds, the viewfinder display turns off ( I guess the meter powers off) at which point you're back to the beginning. It takes one push of the test button to wake up the camera, and another to release the shutter.

The same thing happens when you mount the CST on the hot shoe of a second "master" camera if you want to fire both cameras simultaneously. Taking a picture with the master camera sends a signal via CST to wake up the slave camera. Take another picture and they both fire. This leads to, effectively, a 50% fire rate on the slave - only one picture every two shutter releases at the master, which totally sucks.

So how do we fix this? The "auto-off" function in the menu refers to turning the entire camera off after a certain time. I can't find any setting that will keep the remote camera on standby (i.e., shutter half-way pressed) indefinitely. Shouldn't connecting the receiver basically accomplish this?

Thanks,

Jason

I am sorry, I misred the first post. This should be a function of the prerelease cable. You may wish to contact Flash Zebra regarding this. There may be something specific on a 20D he is aware of, or there may be something else going on.

I have CSRB+'s, CST and Cyber Commander, Zebra cable, 5D MKII and 7D and found the same problems. After more testing, for me it seems to be tied to lens choice. When I attach my 135/2.0 or 17-35/2.8 I get maybe 1 in 5 triggers to work. When I attach any "newer" lenses (24-105/ 70-200MKII) shutter triggers about 95% of time. At first I thought IS had some role in this, because of the lenses that worked, but my 85 1.2MKII works well also. So, in my tests in seems that the lens is some how playing a role in how well the remote camera fires. There is no doubt the CSRB+ is receiving the signal, but something in combination with those older lenses is inhibiting the shutter from opening consistently. I did not find AF or IS to change my results, but if on a job I would certainly prefocus and set to MF.

Now if we some how could adjust delay throughout the whole setup....

My goal was to handhold camera 1, setup up camera 2 as remote, trigger several lights (as one set - combo of AB's and Speedlights) and have everything in sync (flash wise) but it looks as if that is impossible at the moment. Only way to do it would be 2 sets of lights - one for each camera.

Thanks for the posts. I had the same issues. After reading the posts, this worked with my Canon 5D: plug in the cable, press the shutter button once by hand, then continue from that point using the radio transmitter. Now it works great! I'm using the 24-70 L lens.